What Is Layer-0? Rethinking Blockchains with Mainchains and Sidechains

The blockchain world is intricate, featuring a multi-layered technological stack that drives its transformative capabilities. While terms like layer-1 and layer-2 are now widely recognized as evolving protocols, a new entrant has emerged: layer-0. This blockchain protocol acts as the bedrock for numerous coins and tokens traded across various cryptocurrency platforms.

Blockchain Basics Refresher

Before delving into layer-0, it’s important to revisit the fundamentals of blockchain. For those new to the technology, a blockchain is essentially a public digital ledger of transactions, distributed and secured through cryptography. Blockchains typically comprise five layers: hardware infrastructure, data, network, consensus, and application. Each must fulfill distinct roles for the blockchain to function efficiently. This includes storing transaction data and ensuring network-wide consensus before any transaction is validated.

Understanding Blockchain Protocols and the Role of Layer-0

As you explore blockchain technology, you’ll encounter terms like layer-1 and layer-2—labels for different blockchain protocol types, each serving unique roles within the broader ecosystem. While layer-1 and layer-2 protocols, such as Ethereum and Polygon, are more familiar to the community, layer-0 is rapidly gaining attention for its emphasis on scalability and interoperability across blockchains.

Layer-1 Blockchain Protocols

Layer-1 is the protocol most people recognize, as native coins often spark interest in the crypto market. From Bitcoin to Ethereum, these blockchains regularly make headlines during halving events or major upgrades. Layer-1 blockchains are independent networks responsible for transaction processing, robust cryptographic security, and block creation. However, as user demand grows, these mainchains often become congested, slowing transactions and increasing gas fees.

Layer-2 Blockchain Protocols

Layer-2 solutions are built atop existing layer-1 chains, specializing in scalability to alleviate the load on layer-1 blockchains. If you think of layer-1 as a congested highway, layer-2 functions as additional express lanes, easing traffic on the main route. By processing transactions off-chain, layer-2 reduces bottlenecks on layer-1, delivering a smoother, faster user experience across the blockchain ecosystem.

Layer-0 Blockchain Protocols

Layer-0 protocols serve as the infrastructure on which entire layer-1 chains are constructed. They define the architectural foundation and communication standards between blockchains, enabling seamless interoperability and data exchange. By resolving challenges like limited interoperability and scalability bottlenecks in layer-1, layer-0 overcomes the rigidity of monolithic blockchain networks. Their modularity allows blockchains to be tailored to each community’s needs. As this technology evolves, it continues to attract growing interest from developers.

How Does Layer-0 Work?

Layer-0 protocols use a sidechain-based architecture with three core components:

• Mainchain—facilitates data transfer among different layer-1s built atop layer-0.
• Sidechains—application-specific layer-1s connected to the mainchain.
• Inter-chain communication protocol—establishes the standard for data exchange between layer-1s.

For example, Polkadot, a well-known layer-0 blockchain, features a relay chain as its mainchain. Parachains—application-specific layer-1 sidechains—run on this relay chain. Polkadot’s Cross-Consensus Message Passing (XCMP) protocol ensures compatibility and communication among consensus systems. This architecture positions layer-0 as the essential foundation for cross-chain interoperability.

Advantages of Layer-0 Blockchain Protocols

Scalability: Layer-0 increases network efficiency by distributing transactions across multiple layers and can process high volumes without sacrificing security—one of its primary advantages over traditional approaches.

Customization: Developers can build specialized layer-1 chains tailored to unique requirements, leveraging the interoperability provided by layer-0. These range from chains optimized for GameFi to those focused on decentralized applications (DApps).

Innovation: The modular design of layer-0 accelerates development and experimentation, fostering new features and applications in blockchain. For instance, the Venom blockchain utilizes dynamic sharding, automatically adjusting the number and size of shard chains based on current network demand.

Layer-0 vs. Layer-1: Key Differences

For blockchain enthusiasts, comparing layer-0 and layer-1 is inevitable.

Similarities

At their core, both layer-0 and layer-1 are blockchain solutions designed to maximize the benefits of decentralized networks while addressing the blockchain trilemma. Key similarities include:

• Decentralization: Both layers prevent centralized control by distributing governance and operations across multiple nodes.
• Security: Both use robust cryptographic techniques to protect network integrity and data.
• Scalability: Both strive to maximize throughput, process transactions, store data, and reach consensus quickly as network participation grows.
• Transparency: Anyone with access to a blockchain explorer can monitor transactions and verify network status.

Differences

Beyond these goals, notable differences set layer-0 and layer-1 apart:

• Foundational Role: Layer-0 and layer-1 blockchains serve distinct purposes. Layer-0 provides the infrastructure for blockchain creation, while layer-1 manages transactions and consensus directly.
• Scalability Approach: Layer-1 blockchains have struggled with scalability due to monolithic architectures. Layer-0 enables easy transaction routing across multiple chains by promoting interoperability among different layer-1s.
• Flexibility: Layer-0 boasts a flexible, modular design, unlike the more rigid structure of layer-1 blockchains, which are limited by specific consensus mechanisms and data storage requirements.

Leading Layer-0 Protocol Examples

Top layer-0 protocols include:

• Avalanche and AVAX: Avalanche powers multiple layer-1 chains through its P-chain, X-chain, and C-chain mainchains. Each is optimized for specific functions, ensuring high performance and meeting diverse user needs. Avalanche’s high transaction speeds, low fees, robust security, and developer-friendly tools make it a premier platform for building and running GameFi projects, exemplifying efficient layer-0 architecture.

• Cosmos and ATOM: Dubbed the "Internet of Blockchains," Cosmos is a layer-0 designed for modularity and developer flexibility. Updated project documentation highlights the community’s goal of making Cosmos Hub the blueprint for blockchain development across the Cosmos ecosystem. Its interconnected architecture has fostered popular layer-1s like BNB Chain and Cronos, underscoring the importance of robust layer-0 infrastructure.

• Polkadot and DOT: Polkadot is a major layer-0 protocol enabling seamless collaboration among diverse blockchains via its Relay Chain. By leveraging the Nominated Proof-of-Stake consensus of the Relay Chain, Polkadot provides a secure, scalable platform for building specialized blockchains tailored to specific use cases. Its layer-0 design delivers reliable cross-chain interoperability.

Conclusion

With the success of protocols like Cosmos, Polkadot, and Avalanche, layer-0 is widely regarded as a paradigm shift in blockchain design and deployment.

By solving scalability and interoperability issues common in today’s prominent layer-1 blockchains, layer-0 protocols serve as foundational infrastructure, delivering compatibility and scalability through modular sidechains and specialized communication protocols. Layer-0 technology enables a dynamic, interconnected blockchain ecosystem—where diverse, customizable layer-1s built atop robust layer-0 foundations address specific needs and pave the way for the next era of interoperable blockchains.

Layer-0 protocols represent the next evolutionary step in blockchain, offering pathways to more efficient, scalable, and interoperable decentralized infrastructure. As the field advances, layer-0 continues to attract developers and investors eager to shape the future of cross-chain connectivity.

FAQ

What is layer 0?

Layer 0 is the foundational network infrastructure beneath a blockchain, comprising protocols, connections, and hardware that support the entire ecosystem. It provides a scalable alternative to smart contract-based systems.

What is an example of a layer-0 blockchain?

StarkEx is an example of a layer-0 blockchain that delivers scalability and interoperability for layer-1 networks. Layer-0 protocols address the core issues of scalability, interoperability, and flexibility.

What are layer 0, layer 1, and layer 2?

Layer 0 is the foundational blockchain layer (such as Polkadot). Layer 1 refers to main blockchains (like Ethereum). Layer 2 encompasses scaling solutions deployed on layer-1.

Is Bitcoin a layer-0?

No, Bitcoin is not a layer-0. It operates on its own blockchain. Layer-0 refers to foundational protocols that support other blockchains, whereas Bitcoin’s protocol is distinct and not part of layer-0.